b812f6719c
When mirroring runs, the backing files for the target may not yet be ready. However, this means that a copy-on-write operation on the target would fill the missing sectors with zeros. Copy-on-write only happens if the granularity of the dirty bitmap is smaller than the cluster size (and only for clusters that are allocated in the source after the job has started copying). So far, the granularity was fixed to 1MB; to avoid the problem we detected the situation and required the backing files to be available in that case only. However, we want to lower the granularity for efficiency, so we need a better solution. The solution is to always copy a whole cluster the first time it is touched. The code keeps a bitmap of clusters that have already been allocated by the mirroring job, and only does "manual" copy-on-write if the chunk being copied is zero in the bitmap. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> |
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| .. | ||
| qemu-iotests | ||
| tcg | ||
| .gitignore | ||
| check-block.sh | ||
| check-qdict.c | ||
| check-qfloat.c | ||
| check-qint.c | ||
| check-qjson.c | ||
| check-qlist.c | ||
| check-qstring.c | ||
| fdc-test.c | ||
| hd-geo-test.c | ||
| libi2c-omap.c | ||
| libi2c.c | ||
| libi2c.h | ||
| libqtest.c | ||
| libqtest.h | ||
| m48t59-test.c | ||
| Makefile | ||
| qemu-iotests-quick.sh | ||
| rtc-test.c | ||
| test-aio.c | ||
| test-coroutine.c | ||
| test-hbitmap.c | ||
| test-iov.c | ||
| test-qmp-commands.c | ||
| test-qmp-input-strict.c | ||
| test-qmp-input-visitor.c | ||
| test-qmp-output-visitor.c | ||
| test-string-input-visitor.c | ||
| test-string-output-visitor.c | ||
| test-thread-pool.c | ||
| test-visitor-serialization.c | ||
| tmp105-test.c | ||